Carburetor



May 20, 1930. A, ABRATE 1,759,498

CARBURETOR Filed may l, 1924 Patented May 2o, 1930y FICE ATTILIOABB/ATE, OF RIO DE J'ANEIRO, BRAZIL CARBURETOR y Application filed. May1, 1924. Serial No. 710,321. y

This invention rela-tes to a new type of carburetor for internalcombustion engines designed to afford a minimum consumption of fuel atall speeds, ready starting and smooth running under all conditions ofacceleration.

Such results are secured through the particular design of the carburetorandv good arrangement of the whole device, which assures a practicallyconstant mixture and complete combustion, due to the lperfect atomizingand complete vaporization of the fuel in a more suitable volume of airunder all conditions of operation of the engine.

Vith the above objects in view, the invention consists of the featuresof construction and arrangement hereinafter described and claimed in theappended claim.

Vith reference to the drawings:

Figure 1 is a vertical cross sectional view of the carburetor of myinvention showing how the fuel flows from the constant level tank to themain and slow speed nozzles;

Figure 2 is a horizont-al cross sectional view;

Figure 3 is a part elevation and part sectional view through the suctiontube and the air valve, and

Figure 4 is a partial cross sectional view taken on section line 4 4 ofFig. 2.

l/Vith reference to Figure 1: The constant level tank 1 is supplied withfuel through duct 2 and fine wire netting 3 which retains impurities.The fuel is kept at the proper level in constant level tank 1 by meansof a metallic float 4, which governs an arm of a lever 5, see Figure 2,the other arm of which is secured to a ring 6, integral with the stem 7of a conical valve 8, to open or close said valve,

admitting a greater or less quantity of fuel into constant level tank 1,according to the consumption of fuel by the engine. Ring 6 is adjustableto allow, at will, changes in the level of the fuel in tank 1. The duct2 supplies fuel to tank 1, which feeds duct 9 on the top of which isscrewed the main nozzle 10,

feeding likewise duct 11, to which is screwed the slow speed nozzle 12.

The main nozzle 10 is located within the Venturi tube 13, see Figure 3,in the zone of greatest vacuum. Between the double Venturi tube 13 andthe internal wall of the car buretor, there is an annular space 14,communicating with the additional air valve 15, which admit-s greater orless amount of air int-o annular space 14, which communicates freelywith the mixing chamber of the carburetor, see Figures 2, 3.

The slow speed nozzle 12, Figure 1, is screwed on to duct 16, having onits upper end a screw for closing ductI 17. Duct17 is provided,'besides,with small holes 18 in its periphery, see Figures l and 4. These holes18, communicate with the atmosphere through a hole bored in a screw 19,see Figure 4, screwed in the body of the carburetor, communicating atthe same time with duct 20. This duct 20, fed by the slow speed nozzle12, lea-ds to holes 21 and 22, which lead towards the interior of thesuction tube of the engine, respectively coincident with and above thebutterfly valve 24.

The cross-sectional area of hole 22 may be increased or diminished byscrewing in or unscrewing the conical pointed screw 25, manually, in thebody of the carburetor, as it may be needed.

Hole 21, fed in the same manner as hole 22 by means of slow speed nozzle12, serves as an intermediate feeder when the depression caused by theopening of butterfly valve 24 takes place. Above hole 22 there is a hole23 which communicates the suction tube ofthe engine with the atmosphere.Additional air valve 15, see Figure 1, for high speeds, consists of acylinder screwed on to the body of the carburetory over annular space14, which space is located between the double diffuser or Venturi tubeand the internal wall of the car buretor and communicates with themixing chamber of the carburetor. The said cylinder is provided withcircular holes 26 in its periphery, communicating with the atmosphereand registering in greater or less degree with as manyA other similarholes 27 made in the piston, when the latter descends, drawn in by thedepression prevailing in the zone of the diffuser.

lVhenever this vacuum exceeds a certain degree, it acts on the bottom ofthe piston, forcing it to descend more or less, according to theprevailing vacuum, operating against the helical spring 28. Under suoliconditions, the registration of the holes 2G and 27 will be greater orless, allowing a certain amount of pure air to pass into the annularspace lll, variable with the vacuum created by the engine. For thesmooth working of the additional air Valve, small suction holes are madein cover 29, screwedpon to the body of valve 15. This cover is useful inremoving the piston and the spring.

The operation of the engine, starting at slow speed, is as follows. Forslow speed only the slow speed nozzle 12, comes into operation, feedinghole 22, since the butterfly valve 24 remains closed. The small vacuumcreated in the` mixing chamber of the carburetor acts through the hole23, drawing in pure f air from the atmosphere and at the same time actsthrough hole 22, on duct 2O and hole 21 and through duct 20,communicating with the bored hole of screw 19, and with the holes 18which are situated on the periphery of slow speed nozzle 12. Forthwiththe vacuum draws fuel from duct 11, through duct` 17 of the slow nozzle12. As soon-as the fuel comes auxiliary chamber duct also communicating,with the atmosphere at one end thereof bey yond Said auxiliary chamber,two co-axialv Venturi tubes disposed in said main car' bureting chamberand spaced from each other and from the walls of said chamber definingan auxiliary air pocket, a main nozzle disposed with its outlet intheinner Venturi tube at the position of greatest suction, and a suctioncontrolled air valve communicating with said air pocket adapted tointroduce additional air about said main nozzle.

In testimony whereof I ax my signature. ABRATE, ATTILIO.

drawn in through the bored hole of screw 19 making the mixture which isled to hole 22 in. an atomized condition. Y

To increase or diminish the speed of the engine, it will suffice toincrease or diminish the area of hole 22, through the adjustable screw25. To secure .better regulation of the mixture, hole 23 will allow thesupply of more or less pure air to the mixture from hole 22.

Beginning with slow speed and opening gradually the butterfiy valve 24the vacuum prevailing in the suction tube will force the air coming fromthe'entrance to the carburetor to pass under constriction and at highspeed through butterfly valve V24 and the internal wall of thecarburetor at the hole 21.

The vacuum created will be propagated also to duct 20 through hole 22and a greater amount of fuel'will be drawn in through the holes 18 ofthe slow speed nozzle 12, tending to enrich the mixture which, unitingwith the pure air which passes through butterfly Valve 24, maintains theconstancy of the mixture, only the amount of fuel admitted increasingand thus progressively accelerating. the engine speed. If the butterflyvalve is opened more and more, the vacuum which increases with theengine speed will begin to act on the main n ozzle 10 and afterwardsalso on the additional air valve 15, which will supply an increasingamount of airas the supply of fuel through the main nozzle 10 increases.A perfect mixture is thus secured at all engine y speeds.

I claim:

A carburetor for explosion engines compriSing a main carburetingchamber, a suction duct for said engine communicating with

